Defoe scored Pompey's second goal and said there was plenty of buoyancy in the dressing room after the match.
"I thought we played really well, great energy again and everyone is buzzing at the minute, everyone is confident," Defoe told Sky Sports.
"(A) massive three points for us today, we just want to kick on now.
"I was gutted but great spirit from everyone, kept on going, kept on passing the ball really well and when Sean came on and scored with a nice finish I was delighted," said Defoe in regards to Blackburn equalising at 2-2.
"It was important obviously for the manager as well. Things we have done in training - we have done a lot of work in training, training is really good.
"Everyone is delighted with the three points today.
"I think it showed today in the second half that everyone is confident. It was important to get the win today - everyone is delighted."